Hearing aids are electronic instruments worn in or around the ear that compensate for hearing losses by amplifying and processing sound so as to help people with hearing loss hear better in both quiet and noisy situations. Most commonly, hearing loss results from damage to the small sensory cells in the cochlea of the inner ear, referred to as sensorineural loss. Such damage can occur as a result of disease, aging, or injury from noise or certain medicines.
As sound waves enter the ear, they travel through the outer ear, the external auditory canal, and strike the eardrum causing it to vibrate. The eardrum transmits the sound vibrations through the ossicles to oval window and thence to the cochlea. The cocheal is a fluid-filled bony structure that contains the receptor organ for hearing, called the organ of Corti. The organ of Corti consists of tiny hair cells that translate the fluid vibration of sounds within the cochlea into electrical impulses that are carried to the brain by sensory nerves.
The cochlea has two types of hair cells: inner hair cells and outer hair cells (IHC and OHC, respectively) that provide very different functionality. The OHC provide a near-instantaneous compressive mechanical amplification that is frequency-specific and place-specific. The IHC transduce the acoustic input into neural patterns to be sent to the brain. For any given hearing loss, there is usually a mixture of damage to these two hair cell types. The compensation for one type, however, is unlikely to be optimal in compensating for the other. Described below is a method and system for addressing this problem.